1. Field of the Invention
The present invention relates to a cooking method, and more particularly, to a heating method that effectively cooks foodstuffs subject to foodstuffs' properties, assuring foodstuffs safety and saving energy.
2. Description of the Related Art
Following the progress of human civilization, fine culture of food and drink is developed.
To fit different time schedules and to satisfy different cooking requirements, “slow cooker” and “stew-pot” cooking methods are developed.
Slow cooker is a cooking method to cook food using a small power when one is going to sleep at night or to work outdoors at daytime so that one can enjoy the food when wakes up in the morning or returns home after working. Traditionally, the heating power used in a slow cooker is subject to the designed cooking time, for example, 4 hours, 6 hours or 8 hours. Normally, the heating power for slow cooker is about 250 W, or one half of a regular electric rice cooker. However, this traditional design does not meet certain cooking requirements, and a person employing this method may be unable to have food be well cooked or may cause food to be excessively cooked. When cooking food at a low heating temperature, for example, within 20˜50° C., for a long period, microbes may grow on the cooking food. To understand the accurate design principle of slow cooker, the cooking object and properties of food must be studied at first.
The heating process during cooking is primarily to kill bacteria and microbes that are harmful to human body, and secondarily to convert food into an eatable condition for absorption by human beings.
Normally, microbes stop movement when at 60° C. (140° F.). However, harmful microbes on food will be killed only when the temperature reaches 74° C. The temperature range within 15° C.˜52° C. is the most dangerous range where microbes grow fast. Foods will start to deteriorate when keeping under this dangerous temperature range for long. Heating cannot eliminate toxic substances produced by microbes.
Therefore, when employing a slow cooker cooking method, the initial heating power must be able to heat the cooker (cooking pan) to the safety temperature level to stop microbes stop from movement within a predetermined time period. Normally, the cooker shall reach 60° C. (140° F.) within 2 hours after start of the slow cooker cooking method. Except the reason of food safety, heating can convert foods into an eatable form for easy absorption by human beings. For example, cooking by heating can soften meat and decompose starch from a crystal structure into absorptive gel. Further, tough meat is not easy to be thoroughly cooked. Actually, tough meat contains a big amount of collagen that starts to decompose into gel-like condition and to dissolve in water when heated to 60° C.˜65° C. This process requires time; however it is not necessary to heat to the boiling status. Therefore, slow cooker cooking method is very suitable for cooking certain meat, more particularly, beef shank, to a softened status.
Cooking foods of starch group, such as rice, corn and etc., requires a relatively higher heating temperature, about 65° C.˜93° C. so that contained starch can be thoroughly cooked into a gel-like condition.